Plant for centrifugal concentration of ores and like materials



Feb. 17 1925.

O. B. PECK. JR

PLANT FOR CENTRIFUGAL CONCENTRATION OF ORES AND LIKE MATERIALS Fild June 25, 1924 2 Sheets-Sheet 1 INVENTOR O. B. PECK, JR

Febfl'i. 1925. 1,527,074

PLANT FOR CENTRIFUGAL CONCENTRATION OF omas AND LIKE MATERIALS Filed June 23, 1924 2 Sheets-Sheet 2 Patented F ch. 17, 1925.

UNITED STATES ORRIN B. PECK, JR., 0]? LOS ANGELES, CALIFORNIA.

PLANT FOR OENTRIFUGAL CONCENTRATION OF ORES AND LIKE MATERIALS.

Application filed June 23,

T 0 all whom it may concern:

Be it known that I, ORRIN B. PEcK, Jr. a citizen of the United States, and resident of the city of Los Angeles, State of California, have invented certain new and useful Improvements in Plants for Centrifugal Concentration of Ores and like Materials, and my invention preferably has in its embodiment that class of concentrator which operates in successive cycles of alternately accumulating a quantity of concentrates in a rotatable concentrating vessel and then discharging the same during reduced rotation, and the combination of elements in automatic association and operative coordination to carry out the successive steps of such cycles in requisite relative harmony to obtain the results sought.

In the drawings, Fig. 1 is mainly a top plan showing the relative association of elements of my invention, but with some portions partly in section and some not fully illustrated in detail, also with certain concentrating elements positioned for the be ginning of acycle of operation.

Fig. 2 is partly a vertical longitudinal central section and partly a side elevation of the concentrating machine with its feed mechanism, with parts positioned as at the end of the concentrating period of a cycle, ready for commencement of discharge of accumulated concentrates.

Fig. 3 is a side elevation of the divided or two part counter shaft for driving the concentrator, with its clutch and brake as well as some other attached parts, the clutch being illustrated as out of transmission engagement, while part of the brake is illus trated in section and in position for-braking engagement.

Fig. 4 is a central vertical section of the feed valve and its hydraulic operating cylinder, shown functioned to position for feed of material to the concentrator, as would be the case while the concentrator parts are positioned as in Fig. 1, at the beginning and throughout the entire concentrating period of the cycle.

Fig. 5 is a erosssection of Fig. 4 on line 55, Fig. 4, looking in the direction of the arrows, especially showing the comparatively small hole through the piston head.

Fig. 6 is mainly a vertical cross section 1924:. Serial No. 721,647.

of the automatic control member, taken mostly on line 66, of Fig. 1, looking in the direction of the arrows, but revolved to a position relatively 180, showing the mechanism more complete than in Fig. 1 and as just having functioned for commencement of the concentrating period of a cycle of operation.

Fig. 7 is similar to Fig. 6, only illustrating the position of its members shortly beifpre having functioned as illustrated in said Fig. 8 is a fragmentary side elevation of the upper left hand portion of Fig. 6, illustrating the outer end of the valve lever and its associate parts at this end, raised to its fullest extent, in position to be released for downward movement to close its valve, also showing in dotted lines the manner of connection of the valve stem head and the lever.

Fig. 9 is a top plan of one of the graduated control cylinders enlarged, which are shown without complete detail in the automatic control member of Fig. 1, where in the interest of clarity of illustration, the actuating members have, been mostly omitted.

Fig. 10 is a development of the circumferential surface of Fig. 9.

Fig. 11 is a central plan section of Fig. 9, with two of the movable actuating members mounted on it.

Fig. 12 is a plan of one of the actuating members, detached from the control oylinder, and its fastening bolt, the latter having an elongated head.

Fig. 13 is the governor and its driving clutch, illustrated partly in section and partly in elevation, showing the governor at rest, with closed port as it appears in Fig. 1, during the concentrating period.

Fig. 14 shows a side elevation of the brake friction wheel mounted on the part of the shaft which drives the concentrating vessel, and a cross section of the lower part of the brake mechanism with its parts in position of having moved the brake out of frictional engagement, as would be the case while the governor is in position illustrated in Figs. 1 and 13.

Fig. 15 is similar to Fig. 13, except the governor driving clutch is in engagement, operating the governor to open its liquid flow port in position it would be to a greater or less extent during the concentrate discharge period of the cycle.

Fig. 16 is similar to Fig. 14, but with the moving parts of the brake mechanism in position as they would be while the associated governor is in operation as illustrated in Figs. 3 and 15."

Fig.1? is mostly a central cross section of the lower part of the brake members, and a side elevation ofits other parts, illustrated in position revolved 90 with respect to Fig. 16.

Fig. 18 is mostly across section of the governor drive clutch, taken on line 18-18 of Fig-.15. l 1

I wish to first explain that in the accompanyiiigdrawings, to enablegreater clearness' of illustratioirand understanding, the relative sizes and proportions of some elements and members are not maintained as they might best be employed in operation, and that in some instances the illustrations of elements are not complete in detail throughout all figures, but are in the aggregate, sui'iiciently so to render a complete understanding of my invention, and 1138 01)- eration, as well" as to enable its construction.

In carryingout my invention employ a centrifugal concentrating machine preferably of' the kind andtype illustrated and described in application for U. Letters Patent recently filed by me, which operate in successive cycles of accumulating a quantity of concentrates or heavier constltuents, in a concentrating vessel while rotating at a comparatively high rate of speed,'and then discharging the same while l'fiVOlVlllg-itt a comparatively low rate of speed, together with mechanism, members, elements 1 and parts for best relatively and concurrently coordinating and functioning to automatically effect thevarious-steps inthe successive cycles of operation to obtain highest mechanical and technical results;

In the drawings,*2 is a rotatable concentrating vessel,-which'in Fig. 1 is shown partly in horizontal section and in Fig. 2, partly in'vertical section. It is preferably smallest at its feed end and otherwise of the same general form and structure illustrated. l

The vessel is provided with a head 3, at its small end, having an'extended hollow trunnion by which this end rQt-at-ably j'ournaled in a box 1t is also provided T! with a head 5 at its large end, which is se cure'ly and concentricallymrelmted on the end of a hollow shaft 6, which, in'-turn,is rotatably journaled in boxes 7 and 8, as shown, and is provided with a pulley 9, by which rotation may be imparted to the shaft and'vesscl, as desired.

lVithin the vessel is a rotatable core 10, which is securely mounted on the overhanging end portion of a shaft 11, this latter shaft passing into the vessel through the hollow shaft, in which it is journaled, and its outer or opposite .endportion journaled in a box 12. The shaftis provided with a pulley 13, by which it, with the core, may be revolved.

It is preferable to'shape the circumference of'the core, tapering ,to conformto that shape of the vessel, and to make it somewhat shorter than the internal length of the vessel, also of diameter so when the same is positioned in the vessel near the small or feed end, as shown in Fig.1, there will be a comparatively small space 1 1, between the circumferential surface of the core, and the internal diametrical surface of thevessel. Both of these surfaces are-best when made comparatively smooth so the space 14, Figs. 1 and'2, which serves as thematerial flow channel and concentrating passage, will be comparatively uniform.

It will be understood that in operation, for the commencement of the concentrating period of each cycle, the coreis positioned at the small or feedendof the vessel, as

shown in Fig. 1, whichcontracts the concentrating passage, being also: the flow channel to its smallest siae,.and as the'concentrating period proceeds, the progressive separation and lodgment of concentrates in the channel, begins to contract such channel and commences to back up or increase the accun'lulation of liquid and material in the feed end of the vessel, immediately resulting in an increased pressure of such materials lengthways on the core to push or force the core towards the discharge end of the res sel, in such way enlarging the flow channel 1 1, and automatically lessening the endways pressure on the core so as to maintain the size of the flow channel and separating passage practically constant.

To neutralize or counterbalance the pressure on the core towards the discharge end of the vessel, there is provided a hydraulic pressure cylinder 15, which may be securely attached to the outer end of the journal stand 16, as illustrated in Figs. 1- and 2. This cylinder is preferably positioned in ex tended axial alignmentwith the core shaft 11, and is of internal finish suitable for an appropriate piston head 17, to operate therein. r

The piston head while intended not to rotate in the cylinder, rotatably engages a disc 18, which is secured to the contracted end portion of the shaft 11, the shaft extending through the journal box 12 into the cylinder 15, for this purpose, as best shown in Fig. 1. r I

To afford suitable yieldable hydraulic resistance' in the cylinder to the endways pressure on thecore, and at the same time permit desired longitudinal movement towards the large end of the vessel during the concentrating period, as well as to force the core back to the small end of the vessel during the concentrate discharge period of the cycle, I provide it with a suitable yieldable, and preferably adjustable source of water or other liquid supply under pressure, as from a suitable accumulator, or air cushioned receiver 19, which is shown in Fig. 2.

This accumulator should be of adequate size, and may be located at any convenient place with respect to the cylinder 15, to which it is connected by a pipe 20. The liquid in the accumulator should be maintained at as nearly uniform pressure as practicable, to furnish requisite and desired pres sure in the cylinder 15, to suitably balance the opposingendway pressure on the core. The pressure to the cylinder 15, may be further adjusted by a relief or blow oil" valve 21, of any suitable type. To enable better description and illustration, the pipe connections to and from the cylinder 15, are shown relatively positioned 90 differently in Figs. 1 and 2.

In operation, the length of the concentrating period of the cycle is not predetermined, it commences with the core positioned at the small end of the vessel, as above stated, and as shown in Fig. 1, and continues until the core has been gradually forced to its extreme position at the large end of the vessel, as shown in Fig. 2, and as hereinafter explained at which time this period is complete, feed of material to the vessel for concentration is then discontinued; relatively clean water introduced in place of material; the speed of rotation of the vessel much reduced and the accu mulated concentrates or heavier constituents discharged from the vessel, the latter action occurring at relatively slow speed of the vessel while the core is being forced to the small end of the vessel in position for commencement of the concentrating period of the next succeeding cycle.

The pressure to strongly force the core towards the large end of the vessel during concentration, is mostly incident to centrifugal force at high speed of the vessel, on liquid, with its material, being introduced in the small end of the vessel, and as above explained, the pressure of liquid in the cylinder 15, is adjusted to balance this endways pressure throughout the concentrating period, and suitably yield to it as desired, whereas, during the discharge period of the cycle, while the vessel} is rotating at a much reduced speed, the endways liquid pressure on thecore, as a sequence, is not only greatly reduced, but the. centrifugal force then being developed which holds the accumulated concentrates in the vessel is also greatly reduced, these combined changed conditions resulting in the pressure in the cylinder 15, which is maintained constant, then quickly forcing the core to its initial position in the vessel while the ac-- cumulated concentrates are rapidly dis-- charged, as has been before stated.

As further means for accomplishing the various steps in this operation, I provide the outer end of the cylinder 15, with a secondary chamber 22, connecting with the bore of the cylinder by a passage 23, and supply a suitable valve disc 24, adapted to seat over the passage 23, to close the same, as shown in Fig. 1.

The disc 24. is provided with a suitable stem 25, with its end extending through the passage in position to contact with the outer end of the piston head, and open the passage 23, as shown in Fig. 2, at the time the core has substantially reached the extent of its movement towards the large end of the vessel. The disc 2% is normally held in closure by a yieldable member as a rubber cushion 26, suitable for the purpose.

As means for automatically supplying liquid under pressure to cause the several members and elements of my invention to function at times and as desired, 1 provide a hydraulic control, which I will indicate as a whole by the initialing numeral 27.

This control is shown in most parts in plan in Fig. 1, and in vertical cross section in Figs. 6 and 7. It embodies a suitable preferably cast metal frame 28,. which is provided with a liquid pressure chamber 29, Figs. 6 and 7, for liquid under requisite pressure to hydraulically operate the parts desired. This liquid may be supplied from any appropriate source through a pipe 30, communicating with the pressure chamber.

Securely attached to the wall of the pressure chamber 29, and communicating with such chamber are a number of reciprocablc plug hydraulic control valves 31, which are indicated in plan in Fig. 1, and will be termed as control vales. They are shown partly in vertical section and partly in elevation in Figs. 6 and 7. In the latter two figures, for purposes of better illustration,

while operative, these valves are shownv larger than necessary in proportion to some other parts of the control.

The control valves are provided, as above stated, with reciprocable plugs 32, each of which has a liquid port 32 adapted to be normally closed as shown in Fig. 7, but which will be opened for flow of pressure liquid from the chamber 29, when the plug is sufliciently raised, as shown in Fig. 6. The several valves are piped to the various elements, as illustrated in Fig. 1, the functioning of which they control.

As means for operating the control valves, and governing and regulating the times of their respective movements, I provide a slowly rotatable shaft 33, on which are rigidly mounted as many preferably graduated operating cylinders 34, as are required for that purpose, in this instance there being three of such cylinders.

The operating cylinders 3e are partly illustrated in plan in the control in Fig. l, which closely indicates their relative plan association, but areshown without graduations. They are also shown in operating position in Figs. 6 and '7, but are best shown in detail in Figs. 9 and 11, and their graduations best, in development of the circumferential surface of one of them in Fig. 10.

The graduations are placed on the'several cylinders so that the same numbers on each will be in the same axial alignment, in order to better serve as a guide and render quickly possible accurate adjustment or placing relatively pawl actuating member's thereon, which will be herein below explained.

On the circumferential surface of the. operating cylinders are located as many movable actuating members 35 as required, for purposes herein below explained. These members are preferably formed suitably to fit the circumference of the cylinders, and are held to place by a suitable bolt 36, which has an elongated head as shown in Fig. 12, adapted to be passed into the annular channels in the cylinders, and clamp theactuating members securelyto desired places, such method of clamping being best illustrated in Fig. 11.

lVhen it is wished to move any actuating member to another position or adjust-the same on the'oper'ating cylinder, its bolt may be loosened and the member moved, and secured rigidly in its changed position by again tightening the bolt.

To transmit movement from the operating cylinders to the valve plugs 32, 1 procide a lever 37, for each of the valve plugs, which is suitably fulcrumed at 38, Fi'gs. 6 and 7, to part of the control frame '28, with its end nearest the operating cylinder formed into a downwardly extended comparatively short angle portion, in which is pivoted or hinged a pawl 39, preferably normally positionedas illustrated in Fig. 7, with its outer end in close proximity to, or lying on the peripheral surface of its operating cylinder, adapted to contact with the edge of its actuating member, as the latter is slowly carried in that directidnby rotation of the operating cylinders.

The position of these parts in relatively near approachingcontact is shown in Fig. 7, and the relative position of the two members is shown in Fig. 6, justafter they have functioned and caused movement of the valve plug 32, to a position of opening the and otherwise of the r tailer liquid flow port from the pressure chamber 29.

It will be seen that forcing-the pawl along by the actuating member, will carry with it the deflect-ed or angle end of the valve lever 37, and raise the opposite end of this lever upward, and with it, the valve plug which is suitably attached to that end, preferably by means of a head member 40, in the manner'best illustrated in full and dotted lines in Fig. 8.

As means of tripping the pawl to properly release its end from engagement with the edge of its actuating member, there is provided atrip or deflecting member &1, adapt ed to suitably deflect the other end of the pawl downward during its forced movement backward, which results in raising the contacting end of the pawl upward until ithas slid over the top of its actuating mem her, having in the operation, properly raised its associated valve plug to position of open port, as shown in Fig. 6.

It is desirable to maintain an open flow port through most of the several valves a greater or less length of time duringthe cycle of operation,-depending on what the requirements in that respect may be for the particular element which the valve may be serving.

To accomplish this purpose there is a member 42, illustrated in Figs. 6, 7 and 8, which is hinged or linked in suitable position to that end portion of the valve lever, and is provided with a shoulder or notch, positioned and adapted, as the element 42 is'raise'd withvalve lever,to swing in, and rest on the upper part of the valve structure 43, as shown in Fig. 7, and hold the valve plug up with its port open until released as is below explained.

It will be seenthat part of the actuating members 35, are thicker than others, the thinner 'ones being of suitable thickness to operate the pawl to raise the valve plug sufficiently to open'its port, as shown in Fig. 7, while the thickerones are adapted to raise the end of the'valve lever and the moving valve parts somewhat higher, as shown in fragmentary Fig. 8, where the member 42, is shown with its shoulder raised somewhat above its contact point illustrated in Fig. 6.

The contact part on this member 42, is so formed or beveled, that when the valve lever is released in the fully raised position shown in Fig. 8, the member will be deflected out ward inits downward movement by impactwith the frame structure, and permit the valve lever and plug to travel down to their lowest position, which is shown in Fig. 7, thereby closing the flow port through the valve.

The valve plug is provided with a stop collar' le, Figs. 6 and 7, to properly limit its downward movement, and there is a spring 45, to force and hold the plug down in normal position when released by the means for raising the same,

There is preferably one valve and its mechanism embodied in the automatic control, for each movement of the several ele ments which it is intended that the control shall cause to function, employing two valves for operation of each of such elements, except in the instance of particular operations through movement of the valve disc 24, Fig. 2, which will be further explained, and in cases where conditions of operation are such as to permit of the coupling of two or more elements to the same valve, entailing simultaneous movement of such elements.

The operating cylinders 34 are each preferably provided with two channels for the actuating members or their bolts, as shown, and the valves 31 are preferably secured to the wall of the pressure chamber 29, in pairs as indicated in Fig. 1, in suitable relation to the channels, so the pa-wls 39 will properly function with the actuating members to operate their respective valves, as has been above explained.

Any suitable motive power may be employed for the concentrating machine, as an electric motor 46, Fig. 1, which Iprefer to have of the variable speed type, directly connected to the counter shaft of the concentrator drive.

This shaft is preferably in two sections, 47 and 48 respectively, appropriately mounted in journal boxes as shown and is provided with a suitable friction clutch, as a magnetic clutch 49, properly mounted on the adjacent ends of the shafts, and adapted to frictionally engage and disengage the two parts of the shaft when and as desired.

It will be understood that the core 10, of the concentrator, is operated at a constant speed throughout the successive cycles, and that, as has been already explained, the c0nccntrating vessel. except under unusual spe cial conditions, is operated at a relatively high rate of speed during the concentrating period of each cycle and at a relatively low rate during the concentrate discharge periods.

To obtain the constant speed, of the core, its pulley 13, is driven by a belt 50 from a pulley 50', mounted on the constant speed section 47, of the counter shaft.

The preference herein expressed for variable source of power is more especially to facilitate change of speed of the concentrator from time to time to better adapt it to possible radical change in characteristics of material which it may be desired to treat, and not to effect change in speed of the concentrating vessel during its cycles of opera tion. 1

To automatically decrease the speed of the concentrating vessel for the concentrate discharge period, which I will term the discharge period, I provide brake mechanism, which preferably embodies a suitable cast metal open end pan member 51, the open endof which is adapted to receive a suitable flexible diaphragm 52, preferably of strong rubber fabric, which is securely and tightly clamped to the open edge of the pan by a ring 53, rendering the pan a closed chamber with a flexible end, adapted to contain liquid under requisite pressure.

To the central portion of the diaphragm is tightly and appropriately secured a stud 54, as illustrated, which is adapted to be forced up or down with movement of the diaphragm.

The pan or base portion 51, is provided with suitable cars 55, which are illustrated in Figs. 1 and 17, located on diametrically opposite sides of the pan, adapted to engage and securely hinge the lower ends of the brake arms 56, which suitably extend upwards, as is most clearly shown in Fig. 17.

The upper end portions of these arms are adapted to carry friction surfaces to operate on a suitable friction wheel or drum 57, securely mounted on the section 48, of the counter shaft, this section being the one which drives the concentrating vessel from a pulley 58, by a belt 58, as shown.

To produce desired movement of the brake arms. there are provided links or members 59, connected in a hinged manner to the upper end of the diaphragm stud 54, and to the respective brake arms, somewhat above. their base hin ed fastening to the cars 55, as shown in Fig. 17.

Through this form of construction, as the diaphragm is hydraulically forced upwards in the position shown in Figs. 3, 16 and 1.7, the links 59 will pull the brake arms in ward, effecting frictional engagement with the wheel 57, to break down the speed of the section 48 of the counter shaft.

This action of the brake will; result in reducing the speed of the concentrating vessel as desired, the two parts of the clutch 49', at this time being either entirely disengaged torsionally. or in comparatively weak engagament to permit reduction by the brake of the speed of the section 48 of the counter shaft, with little or no reduction in speed of section 47 thereof.

To maintain a desired approximately uniform reduced speed of the concentrating vessel during thedischarge period, there is a governor 60, provided with running mechanism of any suitable ordinary type, preferably variable in operative speed, to which I supply a valwehaving a reciprocable plug 61, as shown in Figs. 13 and 15, adapted to be operated by the ball mechanism of the governor, to bring the liquid flow port of the plug in registration with the opening tln'e eh th Pl s rrelfi thete y ren s the valve at high speed i of the governor.

"During the' slow speed of the vessel for discharge "of concentrates, it is desired to operate the governor at sufficiently high speed, as illustrated infFig. 15, in order to open if Sfl W port so far as necessary to render it effective in regulation of flow of liquid to the bralze pan, with which it is hydraulically connected.

To best effect this, I providea centrifugal clutch 63, partly orlargely shown in Figs. 1, 13, l5,and. l8, whichdsso constructed as tobe cfi'ective in driving the governor, at relatively low speed, and ineffective in such respect at high speed.

This clutch embodies a suitable rotating memberfit, adapted to carry friction rnembers 65, seated at their sidesfartherest from the againstyieldable cushions 66, as shown.

Therotor ea of the clutch has an open end, adapted to receive a friction drive pulley-6T, mounted on the, end of the governor shaft, the relative positions of the clutch v and governor being such as. to permit the pulley 67, to concentrically enter the opening of the clut clnrotor andbe driven by the friction members of the latter as bestshown in Figsl, 15 and 18.

In Figs. 15 and 18, the .frictionmernbers are shown in contact with the governor drivepulley, operating the governor at high speed, while in Fig. 13, these members are shown somewhatreceded, compressing the yieldableine nhers 6: 6, sothe governor is at rest, effecting closure of the liq id flow port in its plug.

The torsional contact of the friction members with the governor pulley, occurs while the clutch rotor is operating at insufficient speed to ,developcentrifugal force necessary to cause such memberslto cornpress the yieldablecushion and recede from driving contact with the governor pulley,

V and ceases, when the rotor is being oper ated sufficiently fast to effect such compres- SlQll ilJlCl cause recession of the fraction members from contact with the governor pulley, afterwhich the? governor will come to r st, ssliownln F el3,which is also the C ndit on. l ustra edas pre ail n in Fi It follgws that the governor drive clutch, which is intended to be ineffective during h qneentratius Perio hould be m P dl ,lOtated during that p eriod, and here slowly rotated during the-discharge Perio e s t I vernor is intended to be re est. uri the. la t r p ri d- To accomplish this, the governor clutch ma be r venby a smallbeit 68, E sfrognit-he vari ble speed shaft 48, operating arcun d a pulley 63, on the clutch shaft, th re y iet th re tiv ly high. and w 512.99, S. oftlieclutch,atth tlesired times- By this manner of driving the governor, from the fact that water under pressure for operating the brake is supplied through it, the speed at which the Shaft/ ifs, will drive the governor clutch, as well as the speed at which the concentrating vessel will be permitted through regulation to revolve during the discharge period, may be predetermined andadjusted by means of the governor and otherwise to. best suit the requirements of the discharge period, and will be automatically maintained through these mediums, substantially as so predetermined.

During this slow speed: period, as has already been explained, the power clutch 4.9, is either torsionally inert or at relatively low driving torque, and the particular control valve through which pressure liquid is supplied to the governor by the pipe '70, shown in 1, is open to admit liquid from the pressure chamber 29.

The pipe 71, which connects the governcr to the brake pan, is-best shown inFig. 1, as also is relief pipe 72, from the brake pan, which is preferably provided with. a suitable valve to adjust the relief flow passage through the pipe. This relief serves to assist in regulatingthe effective liquid braking pressure exerted on the brake diaphragm, for maintaining the speed of the counter shaft e8, as predetermined, and as means of requisite escape of water from the pan when the water is closed offfrom it.

It will be understood that the governor drive clutch, as above stated, is, driven from the ,countershaft- 48, and that such shaft during the concentrating period is revolving at comparatively high speed, also that the governor clutch will not be effective in operating the governor while rotating at such high speed, therefore in order to initially reduce the speed of the shaft and vessel where the governor clutch will drive the governor inoperating regulation, I connect the clutch pan, through a branch pipe to one of the control valves, so the brake will initially receive pressure water directly through this valve and not through the governor, to reduce the speed of the shaft 48 and vessel to a point where the governor clutch will drive it to function in regulation as has been explained.

The actuating member which operates the control valve to which the brake is connected for initial pressure water, should be so adjusted as to permit the valve to remain open only a short requisite time, when it should be closed, necessitating the pressure water to the brake forthe remainder of the slow speed period, to pass through the governor.

As has already been explained, the section 47 of the counter shaft operates at a practically constant speed, and rotation is imparted. from it to the section 48, by the clutch 49, which in this instance is a mag netic clutch of an appropriate ordinary type.

To make this clutch sufliciently effective when desired to drive the vessel at a concentrating speed, it is strongly energized from any suitable source, not shown, through primary electric wires or conductors 73, which are connected to appropri ate contact means 74, adapted to be brought into closed circuit by movement of of a hydraulic cylinder 75, carrying wires 76 to close the energizing circuit in the clutch.

The wires 76 are in operating engagement with ('OlltZlCl) rings 77, of the clutch in the ordinary way, as shown in Fig. 1, furthermore, when it is desired to weakly energize the clutch to supply driving torque during the concentrate discharge period, againstwhich the brake with light pressure will readily be effective, the reverse movement of the piston will break the circuit of the strong current and close it with a weak current from suitable wires 78, as can be understood through illustration in Fig. l of the drawings.

Liquid for operating the hydraulic cylinder 7 5, is supplied from the pressure chamber 29, through the appropriate valves 31, and the pipe 79, as; shown in Fig. l, as will be hereinafter more fully explained, the particular ones of the valves 31 which control operation of the cylinder 75, are predetermined to function at the respective clesired times.

As means for rotating the shaft 33, of the automatic control, which carries the operating cylinders 34, I provide suitable preferable tight and loose pulleys 80, mounted on a shaft which may be revolved from any appropriate source of power, by a belt not shown, which may operate over a drive pulley 81, on said shaft. A belt 82, adapted to operate from the tight and loose pulleys, passes around the pulley 83, which is mounted on the overhanging end of the shaft 33, as shown in Fig. 1, in this manner rotating said shaft.

It is desirable that the operating cylinders 34, of the automatic control, in most cases should be revolved only during part of each cycle, for reasons which will be below explained, and for this reason I-provide means for stopping and starting such revolution when desired, through medium of a device for shifting its drive belt 82, to alternately operate over the respective tight and loose pulleys 80.

This shifting device embodies a suitable hydraulic cylinder 84, positioned and adapted to operate shifting members 85, to movethe belt from the tight to the loose pulley, and the reverse, when desired. In the drawings these shifting members are the piston illustrated as connected directly with the piston rod 86, of the cylinder, but they need. not necessarily be of such detail structure.

The end of the cylinder 84, into which pressure liquid enters to operate the mechanism to stop revolution of the shaft is connected through a pipe 87, to one of the control valves, and the functioning of such valve to procure movement of the belt shifter and stop the automatic control, is adjusted and predetermined. as desired, as will also be hereinafter more fully explained. It is not necessary to hold this particular control valve open a length of time in its operation, so the member 42, is omitted in this instance, enabling the valve to close quickly when released after being opened.

The reverse movement of this cylinder 84, for starting rotation of the shaft 33, is effected by pressure liquid from the hydraulic cylinder 15,, when the valve disc 24, is pressed back through extreme endways movement of the core, this resulting when the core has moved fully to the large end of the concentrating vessel in completion of the concentrating period of the cycle, this movement, requires a time not predetermined, being the sequence of accretion of heavier constituents in the vessel.

A suitable pipe 88 serves to connect the cylinders 15 and 84, as shown in Fig. 1.

During the concentrating period material for treatment properly pulverized and mixed with liquid sufiicient to enable it to flow freely, is delivered for feed into the concentrating vessel, through a pipe 89, connecting to a feed valveillustrated mostly in section inFigs. 2 and 4, and which as a whole is indicated by the initialing numeral 90.

The valve 90 embodies a suitable barrel portion 91, with a short open end pipe 92, extending into the small or feed end of the concentrating vessel, as shown in Figs. 1 and 2, terminating therein, in a manner adapted to deposit the material to be operated on, at this end of the vessel in position to here accumulate to the extent desired, in the space between this end of the core and vessel. and, actuated by centrifugal force, to be forced to progressively flow through the channel 14.

In such movement through the channel the desired mineral bearing or other desired heavier constituents are separated and deposited in a progressively forming accre tion in said channel, while lighter constituents and liquid pass on through to the large end of the vessel, and out through appropriate discharge holes 93, in the vessel, and are caught by a suitable hood 94, surrounding the large end of the vessel, for this purpose, as shown in Figs. 1 and 2.

The hood is provided with an internal channel or opening in suitable annular alignment with the discharge holes 93 adapted to catch the material discharged through the latter, so the hood will guide the same to its lower portion and out through an opening 95, shown in Fig. 2.

To supply clean or relatively clean water during the concentrate discharge period as desired, there is a pipe 96, communicating with any suitable source of such liquid, not shown, which also connects with the feed valve 90, as illustrated, so when desired while material for concentration is notpassing through the valve, such clean water may be flowed through it, into the vessel by means of the pipe 92. The parts of the valve are illustrated in Fig. 2, appropriately positioned for this purpose. hile in Fig. 1 they are intended to be in a reverse position, in the manner shown in detail Fig. 4, appropriate for feed of material to the vessel.

Both the pipes for material and water are connected to appropriate sources of supply, not shown, as has been stated, and each is provided with an ordinary appropriate valve, not shown, to regulate the volume of flow through them.

Within the barrel of the valve, as best shown in Figs. 2 and 4, is a valve disc or closing member 97, which is carried in the barrel by a reciprocable rod 98, passing through a valve seat 99, preferably positioned near the longitudinally central internal part of the barrel, as shown.

The material :Eeed pipe 89, preferably connects with the upper end ofthe valve barrel, the opening into such pipe being positioned and adapted to be closed by the valve disc 97, in its full movement in that direc tion, which position is shown in Fig. 2.

The water pipe 96, is connected to the barrel, as shown, on the opposite side of the valve seat 99, to that of the material feed pipe 89, while the pipe 92, extending into the vessel, is preferably connected on the same side of the seat as is the feed pipe 89. Therelative positions of these connections are well shown in Figs. ,2 and 4.

To effect movement of the rod98 carrying the'disc 97, for opening and closing the passages in the valve barrel to start and stop flow of material or water through the valve, as desired, I provide a hydraulic cylinder 99, in connected operating conjunction with the valve barrel 90.

This cylinder is formed suitably to serve the purposes intended, as illustrated. It is provided with a piston 100, somewhat elongated, being considerably smaller in diameter throughout its central portion than the bore of the cylinder. and with an enlarged portion at each end appropriate to there form suitable piston members.

The barrel 91, of the valve, andthe cylin der 99, are preferably established in such relative positions as to enable the rod 98, to enter and operate in both of these members, passing through appropriate ordinary pack ing boxes to prevent leakage at these points. The rod extends suthciently into the cylinder to connect to the end of the piston 100 therein, so that, as the piston is moved hydraulically, the rod will carry the disc 97, to function in its purposes within the valve barrel.

The length of the rod, as well as the spac' ing of the members and elements of both the valve, and its coordinating cylinder 99, should be such as to properly effectuate the purposes intended.

As means for hydraulically moving the members of the cylinder 99, for operating the feed valve, and to time, control, and regulate such movements as desired with re lation to other steps in operation of my invention, I provide the cylinder 99 with suitable hydraulic pipes 101 and 102, connected in position to supply pressure at their respective ends of the piston 100, as best shown in Figs. 2 and 4, the pipe 101 being employed when it is desired to stop flow of liquid and start flow or feed of material to the concentrating vessel, by moving the valve disc 97, as shown in Fig. 4, which is intended to be the position of these parts during the concentrating period, the relative positions of the members of the con centrating machine being shown in Fig. 1, as appropriate for commencement of this period, and. the pipe 102, is employed dur ing the concentrate discharge period, when feed of material is stopped and relatively clean liquid introduced, as has been before stated, this position is illustrated in Fig. 2.

The pipes 101 and 102 are each intended to be connected to one of the control valves 31, as is shown in Fig. 1, and the particular actuating members 35, which operate these valves are to be positioned and adjusted on the circumference of the operating cylinders 34, suitably to cause the respective valves 31, serving these pipes to function relatively, as well as with relation to other steps and movements in the cycles of operation, to effect feed of material and water to the vessel, through the mediums which have been explained, as and at the times desired As means of. releasing the water which may be static in the full end of the hydraulic cylinder 99, when it is desired to force a reverse movement of the piston 100, by ad? mission of pressure liquid in the opposite end, I provide an escape pipe 103, as shown in Figs. 2 and 4, and through both of the enlarged ends of this piston, I provide a comparatively small opening 104, indicated in dotted lines in Figs. 2 and 4, and shown in plan in Fig. 5, which will serve as means of desired relief and escape for such liquid, but are too small with relation to the pres clearly illustrated in Figs. 2

sure pipes 101 and 102, to materially effect the prompt movement of the piston.

The escape pipe should be located in the central portion of the hydraulic cylinder so at all times to be positioned between the large ends of the piston, as shown in Figs. 2 and 4E.

The hydraulic cylinders t5 and 84, both appearing in Fig. 1, are of the same internal construction as the cylinder 99, which is and 4, although the cylinder 99 is of difierent size than the others, it therefore does not appear necessary to further illustrate them, also their relief pipes appear obvious without initialing them.

The concentrating machine structure embodies a suitable bed plate 105, on which its other appropriate parts are mounted, and other coordinating elements and members entering into my invention are suitably relatively positioned and appropriately mounted to operate, and coordinate to effect the results desired.

It will be understood of the automatic control with its operating cylinders 34, is intended to be revolved one revolution during each complete cycle of the concentrating machine, and in predetermined relative times during such revolution to perform its purpose in effecting suitable function desired, these separate and relative movements being predetermined and relatively timed by the position which the several actuating members 35, are secured on their respective operating cylinders.

The speed of revolution or movement of the shaft 38, is fixed to best suit the particular operation, and unless the conditions of the operation materially change, such speed preferably remains the same, whereas the length of the concentrating period of each cycle, is not predetermined, but is automatically determined by the length of time required to progressively accumulate a load or quantity of concentrates in the concentrating channel, suflicient to gradually and automatically force the core member to its fullest extent towards the large end of the vessel, and open the valve disc 2st, as shown in Fig. 1.

This length of time may be effected by several causes, one potent cause being the content of a greater or less proportion of concentrates or heavier constituents inthe material being treated, resulting in more or less quickly forcing the core back to completion of the concentrating period, and another being the feed of a greateror less volume of material to the vessel, which will produce a similar effect.

that the shaft 33,

To compensate this condition, the shaft.

33 of the control is automatically stopped after causing the feed of material to be started at the beginning of the concentrating period, and remains at rest until automatically started, through opening of the valve disc 24, at the completion of the concentrating period, as shown in Fig. 2, when the belt 82 will be shifted and the control will again function, as the shaft 33 is re volved, until again stopped as above explained.

It will be seen that the belt shifting cylinder 84, is connected to one of the control valves by a pipe 106, to enable the control, being properly adjusted, to function and shift the belt to stop the shaft 33, at the appropriate times.

In operation, assuming the necessary pressure water for use through the hydraulic control valves, and for other purposes, as well as other operating requisites have been properly provided, and the various actuating elements 35, have been positioned on their operating cylinders of the automatic control to effect the several steps and movements in the cycles, at times and otherwise as desired, the power for operation having been started, the magnetic clutch is then fully energized through proper movement of mechanism of the hydraulic cylinder 75, to close the strongly energizing circuit, rendering the clutch effective to revolve the section 48 of the counter shaft, and the concentrating vessel at relatively high speed.

If the. driving motor is of a variable speed type, its speed is adjusted as desired, but otherwise the respective belt pulleys may be proportioned to obtain the comparatively high rotation of the concentrating vessel desired for best serving the concentrating period, the core of the concentrator being revolved at a suitable different speed to that of the vessel, usually at a lesser speed, this somewhat depending on the requirements of the material being operated on, the slower speed often serving best on materials composed largely of comparatively coarse grams.

As has already been explained, the core 10, at the commencement of the concentrating period, is positioned at the small end of the vessel, contracting the flow or concentrating passage to its smallest normal size.

Under the above conditions, feed of material is started to the vessel through functioning of the particular control valve by which the feed valve is operated, and the material, including its carrying liquid as fed into the vessel, will accumulate to the extent necessary for operation in the space between the small end of the vessel and that end of the core, and will be forced to flow through the concentrating passage towards the large or discharge end of the vessel.

This material and liquid passing through the channel, will keep it filled so that the liquid will contact with pressure against.

the circumferential surface of the core, and frenrthe fact fth at this s isrexielirihg at a sp eed difirht from the tflstir-f t'aee Of the v'g sisel there fwtll {be a fi ictibrial "ash "or "scrubbing eurr entj generated through medit u n 0f '1'; re liqirid 111 the thin: nel, Whichjshbfild be developed tdstrength, largely; controlled ithr ohghv the differential speed of the Vessel aird core, td pr'eveiit the relatiyely; lighter eelrstttuents of the inate rial: frerh assuming fixe d ledgni ent in the channel, and tbjfca-rry dr tip 1 dtherni on; through to discharge, While permitting the desired relative-1 3 heavier Bthrstitirkzhti rtij'derl the irnpe t usef ce-htrifrigal'fer lodge in the channel, andtq pfegressn ely fo'rhi' in a bed or accretiehtherehr.

As this aecretielr ferihs, gradually C01 1 traeting' the flex v:

channel; the Presser 0t ac euniulated feed inQt-hei small end (if the veisslhvilhjhcrease, resulting hi gradually and agi-555M15 forcing the coretow r ds the large efid 0t the Vessel t6 "make roem iii the eharihel the lodi'ng eehee ti'ates fas well as inaintaiilil ig a 'practieally hinitiifhr apprepriate flew passage; hhtil the Core" has reached its 'eXtfen1epesitiOn tmvardsfthe largeend, and haspressed the: Valve" disc 2%, permitting flew: throttgh the pi ae 88', to h; drarflieallyleperate the belt shitting cylinder 84, forstarting"the shaft 33%"56 that the-valve which ic olitfols themate m feed devices \villgqil'iekly" fhnetieh and effect steppage of feed of material "ahd' start feed (it watertheijie ssel. 1

The cen eehtrat'rng speedfofthe Vessel preferably ni'ain aihed fuiideritlrese "c i id'r-g time, a'shdttirheafter the feed fmateri ar has heerr stop'pedar'ld that) 6f {rater started; sufficient to enable the lighter cbnstitjue tsl of the material itheh iirl pas s get1 j-gug1 the; vessel massoup t6 disehai bei g' fol; lowed and replaced hy tl refre ive ly cllealif Water; 1e'av'1r1g* the substantially clean eon-" centrates bedded ,in' the "eefice'ijtrati 'li'gi as; Sage. a t a The positie of the; actuating member which Causes theL p artieu1 ar "va'h e "to 11110- tioh, controlling epehihg of the strehgly en'- ergizing cm-rent tethe'maghetijc cl'rlteihfand closing the circuit 6f the Weaker eurre iltfi's sueh that at this time it rvill be e'ehie effeet'ri e, so the section 48 of th'e eou ntei" "shaft" will be readily amenable to the" actibnof' the brake, iii redrteihg' and regulating the sijeed under the then 'Weak tersiohal 'enefg (1f the cluth, "and the frictional "impet s nge g dered'hj' the Wash in the cehcentrati ng p as Sage; v .e a t a l The control valve through which pressure Water is ihitially supplied td flwpmka'now opens rendering-the'hrake eifegtiv e 't'b re duee the speed efthe shaft 485121111 the'vessel sufficiently for the governer to' beeomeeffecwattag tiye in 1 regulatiolr, when sueh 1 central valve closes arrd the eojnt'rel eonnectet to the: water W411 they be Vii. "\JJL t e come etfect lyethreug r.

eratie of! the rec htern 1 0t atien the shat S ar'rdtheVesseI, to h "sne'dire Under su eh conditions the, brake a v blesdqadsitio whrch 1s so malntam 5 ion small end of the vessel into its initial position ready for commencement of the concentrating period of another cycle.

During this return movement, the core assists the liquid in dislodging and flowing the bedded concentrates to discharge through the hole out of which the separated relative lighter constituent-s passed during concentration, but however, the concentrates may be diverted to such place as desired by any appropriate means, not shown, asthe same flow from the discharge opening 95, in the hood of the concentrator.

The concentrates are readily and rapidly removed under the above stated conditions, from the fact that while then under influence of comparatively low centrifugal force, they are subjected to highly developed hydrous washing force in the flow channel, as a result of the slow revolution of the vessel, and the relatively high or constant revolution of the core. For a tentative illustration it may be explained that in operation concentrates have been discharged in quantity exceeding one thousand pounds within a period of approximately one minute, without stopping rotation of the concentrating vessel.

It will be understood that the control valve, to supply water to the cylinder which causes the energizing current of the power clutch to be changed, as well as the control valve causing operation of the feed valve, should be timed to suitably function to carry out these respective steps of the cycle, as also the valves controlling other steps of operation should be timed and ad justed to effect desired coordination in per formance of the elements herein embodied and the proper carrying out-of my invention. Q

lVhat I regard as new and desire to secure by Letters Patent is 1. In a concentrating plant for treatment of finely divided materials having constituents of different. degrees of specific gravity, while mixed with liquid, the combination of a concentrating element embodying a rotatable concentrating vessel adapted to operate in cycles, each embracing a perior of collecting a. quantity of heavier constituents at high speed and then discharging the same at relatively low speed of the vessel, and a core member adapted to operate at practically constant speed throughout said cycle. means for effecting such constant speed of the core, means for effecting such relative ly high speed of the vessel, means for effecting and maintaining such low speed of the vessel without stoppage during the discharge period, and means for automatically functioning said several operations of the vessel, and core. "overned in part by accretion of heavier constituents in the vessel. substantially as described.

2. In a concentrating plant for treatment of finely divided materials, having constituents of different degrees and specific gravity, while mixed with liquid, the combination of a concentrating element having a rotatable concentrating vessel, adapted to operate in cycles, each embracing a period of collecting a quantity of heavier constituents and then discharging the same, means for feeding material for treatment into the concentrating element during an. undetermined period of such cycle, governed by accretion of heavier constituents in the concentrating element, means for feeding relatively clean liquid in said element for discharging the accretion of heavier constituents within predetermined time in said cycle, and means for functioning the several members of the plant in the operation thereof, substantially as described.

3. In a concentrating plant for treatment of finely divided materials having constituents of different degrees of specific gravity, while mixed with liquid, the combination of a concentrating element adapted to operate in cycles each embracing a period of collecting a quantity of heavier constituents and then of discharging the same, means for feeding material for treatment into the concentrating element for a period governed by accretion of heavier constituents in the concentrating elements, means for discharging the accretion of heavier constituents from said element during each cycle, and means for functioning the several members of the plant in operation thereof, substantially as described.

4. In a concentrating plant for treatment of finely divided material having constituents of different degrees of specific gravity while mixed with liquid, the combination of a concentrating element adapted to be operated in cycles of collecting a quantity 0 heavier constituents and then discharging the same, means for feeding material for treatment into the concentrating element, automatically governed by accretion of heavier constitutents in the concentrating element, means for feedingrelatively clean liquid to said elements for discharging the accretion of heavier constituents within time predetermined by automatic governing mechanism, and adjustable automatic means adapted to causing the several members of the plant to function, which effect operation of said concentrating element, substantially as described.

5. In a concentrating plant for treatment of finely divided materials having constituents of different degrees of specific gravity, while mixed with liquid, the combination of a centrifugal concentrating element. adapted to operate in cycles, and having a rotatable concentrating vessel adapted to collect a quantity of heavier constituent-s at a comparatively high a speed and discharge the same, atra comparatively low speed, means, .for feeding. material to said vessel at highwspeedsfor an undetermineditime,

governed by accretion of heavier,v constitu; ants, in the vessel, meansfor eflhctingmhs: charge of heavier. constituents during, a predetermined period of slow speed 'of the vessel, means forrotating the-vessel at vhigh. speed for the undetermined period for con.- cntration, means f rslowly rotating, ,said vessel {for a predetermined lperiodflfor di's charging heavier constituent-s,- andumeans. for, functioning the several elements of said plant, during operation, substantially as ,dc-. scribed.

6., In: a concentratingplant for. treatment of finely divided materials, having c011 stilluents, of. different degrees of' specific gravity, While mixed gvvith liquid the com: bination of a centrifugal. concentrating element, having a rotatable concentrating vessel adapted to: operatev in cycles, eaclr embracinga period of collecting quantityof heavier constituents i at a comparatively lngh speed, and aperiod ot, discharging, the same at a comparatively low speed, means-for feeding materizalto; said vessel. at high. speed for an undetermined.time, governed by ac? cretion of heavier constituents, in thevessel, automaticimeans governed .in part, by; 3C? cretion of heavier. constituents in the vessel, for, veiiectingalow speed .ot the vessel, means for rotating the vessel at highxspeed. during an undeterminedperiod of the cycle and atv-lowspeed duringga predeterm ned period of the (cycle, and'means for function? ing the. several, elements of the, plant during operation,, substantially as describeda 7. In a concentrating, plant. .for, treatment of. ifinely divided material, having; constitiu entsofi different; degrees of; specific gravity, whilemixcd With-liquid, the combination of centrifugal, concentrating, elementadapted; to. operate.- in; cycles, having: a r0.- tatableconcentrating vessel adapted to col.- lectya quantity of heavier constituents-rat a comparati vel-y high speed during each cycle, and dischargeythe sameuat-a zcomparatively lo\v-= speed during each cycle, means for teeth ing-wmaterial tosaidvessel, atzhigh speed for an "undetermined; time, governed: v by accretionof heayierconstituents; inthe vessel, an automatic, control member; governed in, part by accretion of: heavier constituents in: the vesseh-l adapted: to effect iunctioningirof means for introducing j feedv of material, to the vessel, and; stopping; said deed; for :reducing the p oWer; torque driving the vessel; and for operatingthe vessel: at: slowzspeed fore-2a predetermined time for discharge rot heavier constituentsnand meansufor: supply.- ing operating power to: said plant; substan-v tiallyvcas; described. i

8." In a concentrating plant for treatment of finely divided inaterial, havinggconstituents of different idegreesof specific gravity, While mixeduwith liquid, embodying a centrifugal concentrating. element adapted r to operate in cycles embracingiseparate periods of accumulating;heavier constituents and then discharging, the same, havingt aiconcentrating vessel adapted to be operatedat relatively high speedfort-concentrationdun ing an undetermined, period of the cycle and at a, relatively slow "speed during 3 the con centrate'discharge periodaof said cycle, and a diiierentially rota-table coref' member adapted to. operate atr a practicallyconstant speed throughout the cycle, in combination with a substantially constant speedpowor element, an a-utomaticwcontrol member, in part I'governed by accretion t of, heavier constituents in the, vessel adapted to efiiect functioning of means for accclerating itlie vessel vtor concentrating.speech; for supplying, feed ofi material lto the vesselv and dis? continuing such teed mid-supplying relatively clean water to the vessel, anddiscontiime ing the same, for -reducing,andmaintain ing the concentrating: vessel at relatively low speed during thedischargeperiod, and means for maintaining the speed 0t the core member s at practically constant speed throughout thecycle, substantially -as-described.

9. Inwa concentrating plant for treatment of finely divided. material, having constituents lot different; degrees of specific= gravity, While mixed with liquid, embodying a concentnating! element adapted to operatewin cycles each; embracing concentrating period and a discharge period of heavier COHStitur ents and having a concentrating; vessel adapted-to: bev rotated; at relatively high speed during the concentrating period, and at: (i-relatively slowspeed during: said discharge period, and: a differentially irotatable core member adapted to operateyat a :practically. constant speed throughout the I cycle, in=;'co1-nbination with? an automatic control member, adapted I to. effect: functioning: of means: for -.acceleratinggther vessolv for. con centrating speed? for: supplying feed of l ma:- teriali to I thew vessel and discontinuing such feed; means for :supplying: relatively clean Water: vto the vessel for? discharging heavier constituents and means for reducing; and maintaining-the concentrating; vessel at: rel-r ativelyrequisite low \speed during; the niechargerperiod; substantiallyi as: describedu 10.; In a. concentraiingaplant ton treatment of? finely I divided"; 1 material, ohav-ingq con? stituents ofi differentudegrees -.of" specific gravity, whileimixed iwith liquid; embodying a concentrating element adapted to, operate iii cycles; each embracing. an undetermined concentrating 1 period and ia discharge period of heavier constituentsg andr having a com ccntrating vessel adapted? to 'be rotuted ai relatively high speed during the undetermined concentrating period, and at a relat-ively slow speed during said discharge period, and a differentially rotatable core member adapted to operate at a practically constant speed throughout the cycle, in combination with an automatic control men ber, adapted to effect functioning of means for accelerating the vessel for concentrating speed; means for supplying feed of material to the vessel and discontinuing such feed; means for supplying relatively clean water to the vessel for discharging heavier constituents; for reducingand maintaining the concentrating vessel at relatively requisite low speed during the discharge period, embodying a governor connected to said automatic control, adapted to supply liquid under pressure to a hydraulic brake for engaging means driving the concentrating vessel, and means for maintaining the speed of the core member at a practically constant speed throughoutthe cycle, substantially as described.

11. In a concentrating plant for treatment of finely divided material, having constituents of different degrees of specific gravity, while mixed with liquid, a concentrating element adapted to operate in successive cycles, each embracing a period of accumulating and then discharging a quantity of heavier constituents, embodying a concentrating vessel adapted to be operated at relatively high speed during an undetermined concentrating period in said cycle, and at a relatively slow speed during a predetermined period in said cycle for discharge of heavier constituents, and a core adapted to be rotated at a practically constant speed throughout the cycle, in combination with means for driving said concentrating element embodying a shaft, with means for operating the same at requisite constant speed, and provided with transmission means for operating said core member at a predetermined speed, and a shaft in extended axial alignment with said shaft, having transmission means for operating said vessel, said former shaft provided with the driving member of a clutch, positioned and adapted to torsionally drive a member of said clutch mounted on the latter shaft, automatic means in part governed by more tion of heavier constituents within the vessel for effecting variation in the torsional energy of said clutch, means for automatically controlling the speed of the concentrating vessel at reduced rotation during the discharge period, and means for accelerating the vessel for concentrating speed, substantially as described.

12. In a concentrating plant for treatment of finely divided material having constituents of different degrees of specific gravity, while mixed with liquid, the combination of a concentrating element adapted to operate in cycles of undetermined duration, of collecting a quantity of heavier constituents, and then of discharging the same, embodying a concentrating vessel adapted to rotate at relatively high speed during an undetermined concentrating period in said cycle, and at a relatively low speed for a predetermined period of said cycle for discharge of heavier constituents, means for effecting such speeds, and an automatic control member for controlling the functioning of said latter means, adapted to operate. in cycles of predetermined time, being less than the undetermined length of the cycle of the concentrating element, and to be stopped for the remainder of the undetermined cycle, means embodied in said control for effecting stoppage thereof, and means governed by accretion of heavier constituents in the vessel for starting said control at the end of the concentrating period, substantially as described.

13. In a concentrating plant for treatment of finely divided materials having constituents of different degrees of specific gravity, while mixed with liquid, the combination of concentrating element adapted to operate in cycles each embracing a period of collecting a quantity of heavier constituents, and a period of discharging such constituents, embodying a concentrating vessel adapted to operate at a relatively high speed during an undetermined concentrating period in said cycle, and at a relatively low speed for a predetermined discharge period in said cycle, an automatic control member adapted to operate in cycles of predetermined time, being less than the undetermined length of the cycle of the concentrating element, and to be stopped for the remainder of such uncletermined cycle, means embodied in such control for effecting the stoppage thereof, means governed by accretions of heavier constituents in the vessel for starting said control at the end of the concentrating period, means for effecting the relative high and low speeds of the concentrating vessel, hydraulically connected to valves embodied in said automatic control, adapted to effect functioning of said latter means, and adjustable means embodied in said control for effecting operation of said valves, substantially as described.

14. In a concentrating plant for treatment of finely divided materials having constituents of different degrees of specific gravity, while mixed with liquid, the combination of a concentrating element adapted to operate in cycles of successively collecting a quantity of heavier constituents and then discharging the same, embodying a concentrating vessel adapted to operate at relatively high speed during concentration for an undetermined period, and at relatively 

